Due in part to the increasing cost of fossil fuels, such as oil, and to a trend toward the utilization of more environmentally friendly “green” energy production methods, there has been an increase in the amount of energy generation systems utilizing wind turbines in recent years. This trend shows little sign of reversing. Thus, a need exists to provide reliable components for wind turbine systems.
Components of wind turbine systems that present significant engineering design challenges are the turbine blades. A wind turbine generally becomes more efficient as the length of the turbine blades increase. An area over which a wind turbine may capture energy from moving air increases with the square of the length of the turbine blades of the wind turbine. For example, a wind turbine having turbine blades 10 meters in length may capture energy from wind passing through a cross-sectional area four times that of a similar wind turbine with turbine blades five meters in length. Thus, there is a trend toward the production of wind turbines with turbine blades having significant lengths, for example, up to about 50 meters or more.
It is desirable that wind turbine blades have sufficient mechanical strength and stiffness to support their own weight without significant deformation and to resist deformation due to the force of wind on the blades during operation. Wind turbine blades also desirably have sufficient flexibility to elastically deform rather than break upon the application of a sudden force, for example, from a gust of wind. The flexibility of wind turbine blades should be limited, however, so that the blades do not flex to a degree such they impact a tower of the wind turbine. It is further desirable that wind turbine blades be formed of low weight materials and structures so that a wind turbine may include turbine blades having low mass that can more efficiently capture energy from wind, for example, under conditions of low wind speed. The desire for a wind turbine blade to exhibit mechanical strength, stiffness, and low weight presents engineering challenges in the design of wind turbine blades, especially in wind turbine blades having significant lengths.